1. Field of the Invention
This invention is in the field of medical instruments, and relates in particular to nasal dilating instruments.
2. Description of the Prior Art
For the dilation of the nostril and lower nasal passage to facilitate examination thereof, the conventional prior art procedure is to employ a nasal speculum which attaches to an associated illuminating device. The conventional nasal speculum of the prior art is metal, having one fixed and one moveable jaw or spreader. The spreader jaw is unitarily joined at generally right angles with a lever grip. The spreader and lever pivot about a pin or other axis passed through their junction. The illuminating device and speculum attachment are grasped by the fingers while the thumb operates the lever grip and spreader. The speculum jaws are inserted into the patient's nostril and the spreader opened outward dilating the nostril. The illuminating device provides a beam of light which is directed into or toward the nasal passage in order to facilitate examination. The speculum/illumination assembly is biased for use by one hand or the other due to the asymmetrical configuration of fixed jaw, spreader and lever grip.
The use of metal in producing a speculum for use in dilating the nasal passage has several drawbacks. It is costly and therefore makes an adequate supply of specula financially untenable in any but a large clinic. The metal specula must be marketed as reusable items making it necessary to sterilize them between usages. In a busy clinic this is impractical and sterilization is therefore frequently inadequately effected by the use of an autoclave. The insertion of metal speculum jaws is often uncomfortable due to the coldness of the metal. Finally, the light reflective qualities of metal jaws confuse the passage of the light beam into the nostril and hinder the physician in his examination.
The asymmetry of the conventional speculum also provides difficulties. Besides biasing the use of the speculum/illuminator assembly toward use in one hand or the other, the opposition of a moveable jaw with a fixed jaw causes the nostril to be unevenly dilated when the speculum jaws are opened. Centering a light beam along a nasal passage thus dilated is extremely difficult. The physician has little chance of gaining a clear, unobstructed view of the nasal interior. Also, the fixed jaw partially obstructs the light beam and therefore reduces the amount of light which reaches the nasal objective.
Attempts to improve the prior art procedure for dilating the nasal passages are disclosed in U.S. Pat. Nos. 1,014,076; 1,595,378; 1,695,107; 3,664,330; 3,841,318; and 4,201,217. Disclosed in U.S. Pat. Nos. 1,041,076 and 4,201,217 are devices intended to facilitate breathing, especially while asleep and prevent the collapse or other closure of the nasal passages. These devices are not suitable for the examination of the nasal interior insofar as their very insertion visually obstructs the nostril opening. U.S. Pat. No. 1,695,107 shows an invention intended for the heat treatment of the interior nasal tissues. The lamps are extended on arms that open due to a ratcheting device. The lamps provide no usable illumination themselves and the general configuration of the device makes it unsuitable for use as a speculum. A fiber optic tool is disclosed in U.S. Pat. No. 3,774,330 and is comprised in part by a speculum of fiber optic material, light cable, and microscope-like viewing lenses. The device overcomes none of the difficulties of cost, sterilization, or one-time use while introducing a number of cumbersome and limiting mechanical details. A vaginal speculum of unitary construction having dual speculum legs is disclosed in U.S. Pat. No. 3,841,318. The legs of this device are spread apart in its position of repose--i.e., it is biased to its open position--so that this device could not be used for dilation of the nasal passage nor adapted to one-handed use in conjunction with an illuminating device. In U.S. Pat. No. 1,595,378 a speculum/illuminator assembly with dual spreader jaws forced open by a ratchet and thumb-activated similarly to the conventional art is disclosed. The jaws provide no aperture for the insertion of any probe intended for collection of specimens from or manipulation of the nasal passage.
None of these prior art devices provide a suitable non-light reflective, disposable speculum for the symmetrical dilation of the nasal passage allowing for proper illumination of the passage and insertion of a specimen collection probe.